The reigning Premier League champions currently sit 12 points behind neighbours Manchester United at the summit of the table and the Italian suggests that could be to do with the fact they have scored 17 less goals than their title rivals.
"At Southampton, we played very well and we lost 3-1," he said.
"We had other games like the one at (Aston) Villa - against QPR and West Ham - where we missed four or five incredible chances.
"Even in the Villa game, we had other chances to close out the match rather than winning 1-0. It has been our problem this year and has cost us points.
"We have a lot of chances in every game that we are missing. This is the difference at this moment."